1. Field of the Invention
The present invention relates to compositions and method useful in the removal of road film and dirt from vehicles such as cars, trucks, motorcycles, snowmobiles, bicycles, vans, buses, trailers, railway trains and the like. These compositions and methods may be used manually, with hand operated cleaning equipment or in automatic cleaning equipment without the assistance of mechanical action. The methods of the invention may be practiced with a) low pressure, no contact cleaning methods, b) high pressure scrubbing application of the compositions, c) friction wash with low or high pressure fluid application, or any variation of cleaning formats known within the art.
2. Background of the Invention
It is desirable to keep the exposed surfaces of vehicles clean for reasons which include at least maintaining the appearance of the vehicle, minimizing surface tarnishing of the vehicle, reducing paint wear and fading, and preventing corrosion on the vehicle. Each of these adverse affects on vehicles are at least in part contributed to by materials which collect on the vehicle during use and storage. It is well known that regular surface care and washing of the vehicle can assist in maintaining the appearance of the vehicle and can even extend its useful life where corrosion damage is concerned. It is therefore desirable to have products available to the market place which can assist in the cleaning and washing of vehicle surfaces.
Unfortunately, the roadways are not uniform in the materials which contribute to the deposits left on vehicles. The composition of materials transferred from the roadways to cars (often along with moisture from the surface of the roadway) even changes with the seasons. The more obvious changes in the compositions of the road surface contaminants transferred to vehicles occur during the Winter, when anti-icing materials (e.g., salt, pumice, organic solvents such as polyethylene glycol from anti-freeze solutions, sand) are regularly applied to the roadways. The salt used on roadways may often contain mineral oils or vegetable oils as an additive. Less obvious roadway contaminants may appear where agricultural materials used on fields in the Spring and Summer may run onto the road surfaces. Incompletely burned hydrocarbons, leaking vehicle fluids, and spills also contribute to the mix of road dirt which can be transferred onto vehicles. This vast variation in possible materials which may accumulate on cars is also complicated by the fact that soil compositions vary from region to region.
It is commercially undesirable to have to provide a vast array of cleaning solutions or concentrates from which cleaning solutions must be prepared which have to be chosen on the basis of the type of road-film which is thought to be present on a vehicle. The use or need for a wide range of different cleaning solutions would require increased work in designing, packaging and formulating specific cleaning compositions, and would require the user to select the appropriate cleaning solution for each particular vehicle to be cleaned. This would be a very undesirable situation. It is therefore important to attempt to provide cleaning solutions with the widest range of capability with respect to the removal of the most common types of road-film and dirt from vehicles. This is not any easy task because, as noted above, the components of the road-film might comprise organic materials, inorganic materials, hydrophilic materials, hydrophobic materials, acidic materials, or basic materials. It has therefore been a difficult task in designing cleansing compositions for the removal of road-film from vehicles which have a broad range of applicability for the different types of film which may be deposited on the vehicles.
Some mechanical action and/or aggressive fluid application pressure may be necessary in some application to remove traffic film. This can also complicate the compounding of the solutions as certain ingredients useful at lower pressure applications may cause foaming when used with stronger mechanical forces or higher pressure applications. If too high a fluid application pressure is used, the pressure can damage the surface without removing the traffic film. Prior cleaners remove some dirt but the traffic film was not completely removed. Additionally, attempts at providing cleaning solutions which are compatible with the cleaning of such significantly different soil compositions has encountered a problem wherein the ingredients of the proposed cleaning solutions are incompatible, either reacting with one another or separating during storage. The use of hydrofluoric acid solutions, although effective in cleaning certain clear metal surfaces, may be avoided where possible in commercial operations and requires careful control in industrial settings because of the corrosive strength of the HF.
U.S. Pat. No. 4,093,566 describes a phosphate-free spray cleaner for metals utilizing sodium metasilicates, sodium carbonate and EDTA dissolved in water with an ethoxylated wetting agent.
U.S. Pat. No. 4,153,571 describes a heat dependent alkali gel cleaning composition based on alkali metal hydroxides and various nonionic surfactants. Also, U.S. Pat. No. 4,099,985 describes the combination of sodium metasilicate, alkali metal hydroxide and non-ionic surfactants in an aqueous system for cleaning metal surfaces.
U. S. Pat. No. 4,284,435 describes a cleaning composition and method for removing road film from transportation vehicles without the necessity of mechanical brushing or wiping of the surface using high pressure spray equipment. The composition comprises 2 to 30% by weight of chelating agent; 1 to 12% by weight of a bis(ethoxylated) quaternary ammonium compound; 0.5% to 5% by weight ethoxylated alcohol nonionic surfactant; 0-5% by weight sodium metasilicate and water. This concentrate is diluted with water and applied to the surface at a pressure of above 400 psi. Among the chelating agents described are ethylenediamine tetraacetic acid (EDTA)and its salts and hydroxyethylenediamine triacetic acid (HEDTA) and its salts.
U.S. Pat. Nos. 3,123,640 and 3,141,905 describe cation-active surface active chemical compounds, the latter patent specifically describing their use for bactericidal, germicidal, antiseptic, algaecidal, fungicidal, textile softening, corrosion inhibition, antistatic, emulsifying, foam modifying, ore beneficiation, and various other purposes. The cation-active compounds are quaternary ammonium compounds derived from lower monoalkyl dialkanolamines. The cation-active compounds include a) dialiphatic, dialkoxylated quaternary ammonium compounds, and b) monoaliphatic, trialkoxylated quaternary ammonium compounds, as described by formulae in the patents.
One other significant problem with the design of washing solutions is the fact that where the cleaning product to be used in a wash is attempting to remove materials with different properties (e.g., water-soluble and oleophilic materials), the ingredients for the wash solution are likely to be incompatible. Therefore instability in the stored washing compositions and in the diluted wash solutions is highly likely. This instability may take the form of reactivity between ingredients and physical incompatibility between compounds which leads to separation of components or phases. These incompatibility effects can lead directly to reduced performance in the washing process and variability in the performance of the washing process.
The present invention describes a concentrate and a ready-to-use or diluted formulation for an aqueous vehicle cleaner which can remove a wide range of different types of traffic film using either low pressure application, hand pressure application, water jet spray apparatus or other manual or mechanical washing systems. The compositions of the present invention may comprise, for example, one or more solutions that each or collectively contain or comprises:
a) at least one anionic surfactant. These anionic surfactants may be selected from the preferred group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, secondary alkane sulfonates and alkyl sulfates, or may be selected from a more general group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, secondary alkane sulfonates, alkyl sulfates, alkyl ether sulfates, phosphate esters, alkyl ethoxy carboxylates, sulfosuccinates, and soap (e.g., potassium cocoate);
b) at least one poly[oxyalkylene] ammonium cationic surfactant, and
c) an alkaline agent.
Optional additional ingredients may comprise at least one polycarboxylic acid chelating agent (preferably an aminocarboxylic acid chelating agent), at least one non-ionic or amphoteric surfactant, at least one hydrotrope, and at least one silicate. The alkaline agent may provide a pH (when the finished product is diluted to 0.5 to 5% by weight in water) will be between about 9 to 13. The concentrate may be provided as a one-part or two part solution. Certain formulations have been found to be shelf stable as one-part concentrate or ready-to-use solutions, even with significantly different properties amongst the components. The compositions may optionally and preferably contain silicates such as metasilicates, orthosilicates (such as in the form of sodium or potassium metasilicate or sodium or potassium orthosilicate) or other materials to buffer or support the alkalinity of the solution up to about 1-2% by weight in the diluted solution, and to provide additional metal protection. The compositions of the invention are also used in cleaning processes for surfaces, especially vehicle surfaces in car wash systems. The compositions are used in such processes where there are multiple liquid application steps and where at least one of the liquid applications comprises at least one composition according to the present invention.
The present invention relates to a cleaning product which may be provided in a concentrate, liquid, powder, solid or ready-to-use formulation, the product having a capability of cleaning a wide range of soil-film, dirt, oils, deposits and the like from vehicle surfaces with minimal damage to the surface of the vehicle, while using less toxic and harsh materials than hydrofluoric acid. The invention comprises an aqueous solution, powder or solid (including the possibility of alcohol or other organic solvents present in combination with the water) with at least three active components therein. The at least three active components comprise at least one anionic surfactant, at least one alkoxylated ammonium cationic surfactant, and an alkaline agent to provide a pH (when diluted to 0.5 to 5% by weight total additives to water) which will be between about 8.0 (preferably at least 9) to 12. There are additional optional additives, some of which are preferred such as at least one polycarboxylic acid chelating agent (preferably an aminocarboxylic acid chelating agent), at least one non-ionic or Zwitterionic surfactant, and other additives defined herein. The compositions of the present invention may include those that comprise, for example, one or more solutions that each or collectively contain or comprises:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, alkyl sulfates, and secondary alkane sulfonates,
b) at least one poly[oxyalkylene] ammonium cationic surfactant, and
c) an alkaline agent, and
d) a preferred optional ingredient, a chelating agent, particularly a chelating agent for monovalent, divalent and trivalent metal ions.
The present invention also comprises a process for the cleaning of a surface, especially a hard surface, more especially a painted hard surface, and most especially a painted vehicle surface (e.g., a car, truck bus, lorry, bicycle, van, mini-van, wagon, etc.). At least one of the composition(s) used in the cleaning of these surfaces comprises the defined alkoxylated (e.g., polyalkylene) ammonium cationic surfactant.
The alkoxylated cationic ammonium cationic surfactant is an ingredient of particular note within the practice of the present invention. These cationic surfactants are commercially available, for example, as Witco Chemicals Cationic quaternary ammonium compounds Emcol CC-9, Emcol CC-36, and Emcol CC-42. A preferred compound is commercially provided as GLENSURF(trademark) 42, which is inaccurately described as xe2x80x9cDiethylammonium Chloridexe2x80x9d in a PRODUCT DATA SHEET provided by Glenn Corporation, which sells the product. The CAS Number for the actual compound is 68132-96-7, its Chemical Abstract name is Poly[oxy(methy-1,2-ethanediyl)], alpha-[2-diethylmethylammonio)ethyl]-omega-hydroxy chloride, and its chemical formula is listed as (C3H6O)nC7H18NO).Cl. The alkoxylated ammonium cationic surfactants used in the present invention may be generally defined according to the formula: 
wherein R, R1 and R2 are independently selected from lower alkyl groups (C1-C4 alkyl groups), R3 comprises a polyoxyalkylene chain, and X comprises an anion (any anion is useful, acid anions preferred, such as chloride, iodide, bromide, fluoride, acetate, phosphate, sulfate, etc.). A preferred type of polyoxyalkylene chain (also referred to as a poly[oxyalkylene] chain) would have the general formula: 
wherein m is from 0 to 30, n is from 1 to 60, and m plus n is from 1 to 60, and n greater than m. It is preferred that the ration of n/m is at least 2, more preferred that n/m is at least 4, and still more preferred that n/m is greater than 5 or even that m=0. It is also preferred that m+n is within the range of 5 to 60, still more preferred that m+n is within the range of 8 to 50, the most preferred being where m=0 and n=35-45 (e.g., 42). The anion is fairly inert in the system except for its solubility characteristics, which are well understood in the art. Simple anions, especially simple or lower molecular weight acid anions such as chloride, bromide, iodide, sulfate, paratoluene sulfonate, acetate, nitrate, nitrite, phosphate, and the like are conveniently selected as the counterion ion in the cationic surfactant. It is an option that the total number of carbon atoms among R, R1 and R2 have a combined number of fewer than 12 carbon atoms (with the possible maximum being 12 carbon atoms). It is an additional option that the total number of carbon atoms in the R, R1 and R2 groups are between 3 and 12 carbon atoms or between 4 and 8 carbon atoms. The most common form of this class of surfactants has R, R1 and R2 as one methyl radical and two ethyl radicals. In describing compounds by structure and formula in the practice of the present invention, it is well understood that substitution of the compounds would be practiced within the background skill of one ordinarily skilled in the art. The ability of these cationic surfactants has been clearly found to be superior to the performance of other cationic surfactants. Some of the other quaternary cationic surfactants have been found to make certain components of road soil more persistent on the surface to be cleaned or even attract certain types of soil contaminants, as compared to the poly[oxyalkylene] ammonium cationic surfactants defined for use in the practice of the present invention. These poly[oxyalkylene] ammonium cationic surfactants (by themselves, but with regard to some of the following characteristics, particularly in combination with other components of this invention) contribute to at least five fundamental beneficial characteristics of the systems of the present invention which are: 1) compatibility with the anionic surfactant (even those that are generally incompatible with commonly used cationic surfactants, 2) improved overall cleaning performance as compared to compositions which are otherwise identical except for the presence of these poly[oxyalkylene] ammonium cationic surfactants, 3) enhanced drying performance in combination with any or all of the remaining components of the compositions, 4) reduced detrimental surface appearance or no detrimental surface appearance (even though the evidence is clear that the compositions of the present invention are persistent and leave material on the washed surface, especially as evidenced by the persistent improved drying rate of the surface after treatment, the appearance of the surface is quite good, with good reflectivity, no dulling or matte-like appearance, and no discoloration), and 5) a substantive appearance to the finish (the solution actually can improve the appearance of the finish, providing good reflectivity, and a polished appearance to the surface). These combinations of properties are best obtained by the use of these polyoxyalkylene ammonium cationic surfactants, especially in combination with the rest of the components described above for use in the present invention.
These compounds are described in U.S. Pat. Nos. 3,123,640 and 3,141,905 as cation-active surface active chemical compounds. The cation-active compounds are quaternary ammonium compounds derived from lower monoalkyl dialkanolamines. The cation-active compounds also include a) dialiphatic, dialkoxylated quaternary ammonium compounds, and b) monoaliphatic, trialkoxylated quaternary ammonium compounds, as described by formulae in the patents, and are useful in the practice of the invention as the polyoxyalkylene ammonium cationic surfactants. Those patents are incorporated herein by reference for the disclosure of the structure of those classes of compounds.
In the description of chemical structures and formulae, where the term xe2x80x9cgroupxe2x80x9d is used, that terminology is specifically intended to reflect the ability of one ordinarily skilled in the art to use substituted or unsubstituted materials from within the defined class. With regard to the specific example of xe2x80x9calkyl group,xe2x80x9d that term would reflect and is intended to cover not only hydrocarbons which literally fit within the definition of alkyl (e.g., methyl, ethyl, propyl, hexyl, cyclohexyl, isooctyl, dodecyl, stearyl and the like), but also those types of susbtituted alkyl compounds which one of ordinary skill in the art would select for minor or specifically intended variations in the physical and/or chemical properties effected by the substitution such as chloromethyl, hydroxy-ethyl, ethylene sulfonate, 4-cyanobutyl, ethylene-ethyl ether (xe2x80x94CH2CH2OCH2CH3), ethylene-ethyl thioether, dodecyl carboxylate (and its ester), 3,4-dibromobutyl, and the like. Where the term xe2x80x9calkyl moietyxe2x80x9d is used, that term encompasses only unsubstituted alkyl. Similarly, the term a xe2x80x9ccompound having the central nucleusxe2x80x9d refers to all chemical compounds which have the identified chemical structure defined for the nucleus, with the option of having substitution thereon which does not alter the bond structure defined in the formula. For example, a central structure of the formula: 
would include, phenyl, para-hydroxy phenyl, 1,3-dichlorophenyl, 2,4,6-trimethylphenyl, naphthyl, benzamidazol (attached through the benzyl ring), and the like, but would not include cyclohexane, piperidine, or the like, as those changes alter the bond structure of the ring. The terminology of a ring or substituent of the formula limits the structure to the specific groups and positions for substitution as shown.
Anionic surfactants are materials well known in the cleaning, detergent, and general materials composition art. A surfactant is generally defined as any compound which when added to water or an aqueous solution increases the spreading or wetting properties of water or the aqueous solution, usually as measured by reducing the surface tension of the liquid. Surfactants often comprise two segments, one segment which is hydrophilic and another which is hydrophobic. Where the segment of the surfactant which is most active in reducing the surface tension of the water contains or comprises an anion (e.g., dodecylbenzenesulfonate), the surfactant is referred to in the art as an anionic surfactant. Where the most active segment is cationic, the surfactant is referred to as a cationic surfactant, and where the most active portion is non-ionic or amphoteric (having both anionic and cationic species), the surfactant is referred to as a non-ionic or amphoteric surfactant, respectively. The anionic surfactant is generally used in an amount which would provide from about 1xc3x9710xe2x88x925 to 3% by weight (preferably about 1xc3x9710xe2x88x923 to 1% by weight) of the applied solution (the diluted solution or ready-to-use solution). Where the concentrate may be diluted from 1 to twenty or more times, the concentration of the anionic surfactant in the concentrate may be, for example, about 1xc3x9710xe2x88x922 to 20% by weight of the concentrate solution.
Examples of anionic surfactants include organic carboxylates, organic sulfonates, organic sulfates, organic phosphates and the like, particularly linear alkylaryl sulfonates, such as alkylarylcarboxylates, alkylarylsulfonates, alkylarylphosphates, and the like. It has been found that only certain anionic surfactants maximize the benefits of the present invention. These classes of anionic surfactants are known within the surfactant art as linear alkyl benzyl sulfonates (LABS), alpha olefin sulfonates (AOS), alkyl sulfates, and secondary alkane sulfonates. These are art recognized classes well understood by the ordinary surfactant chemist.
The preferred chelating agents for metal ions include polycarboxylic acid chelating agents include such natural occurring materials as citric acid and malic acid (and their equivalents) and such conventional synthetic materials such as the aminocarboxylic acid or amine-type carboxylic acid or amine-type acetic acid chelating agents such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetc acid (HEDTA), and the many other chelating carboxylic acids known in the art. A good background on the structure and types of the chelating amine-type carboxylic acids is provided in U.S. Pat. No. 5,013,622 and Archiv der Pharmazie 307(5), pp. 336-340, 1974. The chelating carboxylic acid is generally used in a amount of from about 1xc3x9710xe2x88x923 to 2% by weight of the applied solution (the diluted solution or ready-to-use solution). Where the concentrate may be diluted from 1 to twenty or more times, the concentration of the chelating acid in the concentrate may be, for example, about 2xc3x9710xe2x88x923 to 50% by weight of the concentrate solution. The chelating acids are often provided as metal salts, especially sodium or potassium salts of the acids, such as trisodium hydroxyethylenediaminetriacetate. Amino phosphonates are also suitable for use as chelating agents in the compositions of the invention, and include aminotris (methylene phosphonate) (ATMP), ethylenediaminetetra (methylenephosphonates) (EDTMPA), diethylenetriamine-N,N,Nxe2x80x2,Nxe2x80x3,Nxe2x80x3-penta(methylene phosphonate) (DETPMP) and 1-hydroxyethane-1,1-diphosphonate (HEDP). Preferably, these amino phosphonates do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.
Non-ionic and amphoteric surfactants are also well known in the art. Many of these may contain polyoxyalkylene chains within the molecule, with appropriate end groups altering the hydrophilic/hydrophobic balance of the compound. The oxylakylene component is often selected from oxypropylene (CH2CH2CH2xe2x80x94Oxe2x80x94) or oxyethylene (CH2CH2xe2x80x94Oxe2x80x94) linkages, preferably with the majority or entirety of the groups in the oxyalkylene chain being oxyethylene linkages. More specific known classes of these non-ionic surfactants are known in the literature as non-ionic alkoxylates, non-ionic alkylphenol polyethers, alcohol alkoxylates (e.g., specifically alcohol ethoxylates and alcohol propoxylates), non-ionic condensates of branched chain primary or secondary alcohols and alkylene (especially ethylene) oxides, alkoxylated amines, amine oxides, non-ionic condensates of fatty acids and alkylene oxides, and the like. Examples of such nonionic surfactants are found in xe2x80x9cSurface Active Agents and Detergents,xe2x80x9d Volumes I and II, Interscience Publications and U.S. Pat. Nos. 2,992,108; 3,068,101; 3,210,152; 3,165,409; and French Patent Nos. 1,556,240 and 1,497, 930. Amphoteric surfactants are also well known in the literature and include, merely as examples thereof, betaines (such as amidoalkyl betaines), and the like. Examples of such compounds are found in U.S. Pat. No. 3,573,049. The non-ionic surfactant is generally used in a amount which would provide from about 1xc3x9710xe2x88x925 to 3% by weight (preferably about 1xc3x9710xe2x88x924 to 1% by weight) of the applied solution (the diluted solution or ready-to-use solution). Where the concentrate may be diluted from 1 to twenty or more times, the concentration of the non-ionic surfactant in the concentrate may be, for example, about 1xc3x9710xe2x88x922 to 90% by weight of the concentrate solution.
The alkaline agent to provide a pH (when diluted to 0.25 to 5% by weight total additives to water) which will be between about 8 to 13 may comprise any of the many alkaline agents known in the art, but preferably comprises metal phosphates, metal carbonates, and metal hydroxides, particularly alkali or alkaline metal hydroxides such as NaOH and KOH. The weight percentage of the pH control agent depends upon the strength of the agent and the target goal for the pH. Generally the pH control agent may be used in weight percentages of about 1xc3x9710xe2x88x925% to 1%, 2% or even 3% by weight of the dilute solution, preferably from 1xc3x9710xe2x88x925 to 3%, and more preferably from 5xc3x9710xe2x88x925% to 1.5% or 2.5% by weight of the diluted solution to deliver a pH of from about 8.5 to 13, preferably from 8.5 to 12. This would convert to about 0.2 to 20% by weight pH agent of the concentrate.
Other conventional and non-conventional cleaning solution additives may be added in the practice of the present invention. Where shelf stability of the cleaning product (as a concentrate or as a ready-to-use product) is important, the optional additives should not react with other ingredients to change the performance of the system adversely or cause components to precipitate or separate within the solution. Among specific types of materials which may be optionally added into the system include, but are not limited to quaternary ammonium compounds, fragrances, brightening agents, antifoaming agents, foaming agents, wetting agents, antioxidants, stabilizers, coupling agents, emulsifying agents, solvents and the like. Silicates, such as metasilicates and orthosilicates are a preferred additive and may be provided in a weight percentage of the diluted solution of from about 1xc3x9710xe2x88x925 to 1% or more by weight, preferably from about 5xc3x9710xe2x88x924 to 1%, and more preferably from about 1xc3x9710xe2x88x923 to 1% by weight of the diluted solution. This would convert to about 5xc3x9710xe2x88x925 to 25% by weight of the concentrate solution. The balance of the solution would primarily be water, with other optional ingredients also present.
The above composition is usually provided as a concentrate designed to be diluted with water. The ratio of concentrate to water is within the range of from about 1:300 to 1:10, but may be diluted to any proportion within that range or less efficiently diluted by a lesser amount (e.g., 1:2). The present invention is able to provide an efficient cleaning composition especially adapted to remove road film which may have a wide range of components from transportation vehicle surfaces. The cleaner may effectively remove traffic film without damaging painted surfaces.
The composition of the present invention also includes an ethoxylated primary or secondary alcohol having from 8 to 18 carbon atoms reacted with from 2 to 12 moles of ethylene oxide. It is preferred that the nonionic have from 3 to 8 moles of ethylene oxide, with the optimum being about 7 moles. These nonionic surfactants are difficultly soluble in the concentrate. Therefore the minimum amount which will provide the proper wetting characteristics is preferred.
Compositions within the scope of the present invention may also include the presence of an alkyl dimethyl amine oxide. Amine oxides are alternatively described in the art as amphoteric surfactants. A preferred amine oxide is dimethyl amine oxide.
These materials are commercially available and well-known nonionic surfactants. The following materials are particularly preferred: lauryl alcohol ethoxylated with 3 moles of ethylene oxide (EO), coco alcohol ethoxylated with 3 moles EO, stearyl alcohol ethoxylated with moles EO, mixed C12-C15 alcohol ethoxylated with 7 moles EO, mixed secondary C11-C15 alcohol ethoxylated with 7 moles EO, mixed C9-C11 linear alcohol ethoxylated with 6 moles EO and the like. It is preferred that the nonionic have from 8 to 15 carbon atoms in the alkyl group. When this preferred alkyl group is used the most preferred nonionic is the mixed C12-C15 alcohol ethoxylated with 7 moles EO.
The concentrate of the present invention could be an aqueous composition. The balance of the composition is essentially water. No particular provisions with regard to non-deionized or distilled water is required.
The composition of the present invention is useful in cleaning vehicle surfaces by any type of pressure spraying or non-pressure application with an aqueous solution or a water concentrate mixture having a temperature of as low as 1xc2x0 C., although higher temperature water up to 95xc2x0 C. can be utilized. Generally, it has been found that water having a temperature of from 20xc2x0 C. to 60xc2x0 C., is preferred, with water having a temperature of from 40xc2x0 C. to 50xc2x0 C., being most preferred. It is within these preferable ranges that an energy savings results as hot water need not be utilized to clean the vehicles.
The composition in the present invention can be either pre-diluted before being introduced to the pressure spray apparatus, or can be mixed in situ during spraying. Generally from 1 part concentrate mixed with 300 to 50 parts water will provide effective cleaning. The exact amount depends on the water hardness, the type of soil in the traffic film, the concentration of actives in the concentrate and the like, i.e., with harder water, a more concentrated solution must be used. Also with soils containing particular metals, a higher concentration is desirable for most effective cleaning. Nevertheless, satisfactory results can be obtained using dilutions within the above range although 1:300 to 1:50 is most preferred.
The processes used in the cleaning industry, such as industrial cleaning, spray washing, mechanical washing, vehicle washing (both automatic and hand-washing, no-touch or mechanical, low pressure, moderate pressure or high pressure), utensil or machine part washing, and the like is usually performed in a number of steps used in sequence and in various combinations. It is not unusual for five or more liquid applications to be applied during a complete wash cycle. For example, there may be a first preparatory application (prep wash, prep gun, presoak, prep rinse or pre-rinse) which comprises, for example, only water; water and detergent; water and builder (e.g., phosphate); water, detergent and builder; and these solutions with surfactants therein. There may also be as a second (or first) step a presoak (or soak, or full soak), even after the prep rinse. This application often comprises the major application of detergent/surfactant in aqueous solution (and some or all optional materials such as chelating agents, solvents, etc.), although non-aqueous, organic solutions may be used. The third possible step (or first or second step) that might be used comprises a main wash application, which usually would follow the pretreatment(s) of either the prep rinse and/or soak application, with little or no time delay between steps, although minutes may often pass between steps, even though this is not preferred from a time usage standpoint or wetting standpoint of the solutions and treatments. The main wash may contain most or all of the primary active agents and the optional agents as desired for the specific process and as listed above. Another application (e.g., a possible fourth step) in this sequence may be a xe2x80x9cclear coatxe2x80x9d application, often comprising a non-ionic surfactant, anionic surfactant, optional quaternary compound, buffering agent or pH control agent, solvent, and the like. Any of these steps or combinations of steps may then be followed by a possible fifth step such as a rinse step, with the application comprising water (alone), some lower concentration or solvents and detergents than in one or more of the previous applications, and generally lower concentrations of additives. Another optional step (e.g, a possible sixth step) would be a drying application step which might include an organic, relatively non-volatile solvent (e.g., mineral seal oil, C1-C6 ester, etc.), water, alkyl or aryl quaternary ammonium compound, dialkyl quaternary ammonium compound and any of the other optional ingredients. A main purpose of this application is to facilitate removal (e.g., physical removal, as by run-off or air spray assisted run-off) of the liquid from the surface so that spotting from dissolved or carried components is reduced. This more rapid drying is particularly significant since the potential for residue remaining is lessened and the total time of the wash cycle may be reduced by reduction in the critical drying phase at the end of the wash cycle.
The use of the defined cationic surfactant (comprising a solution of poly[oxyalkylene] ammonium cationic surfactant alone in a water carrier, a solution with water and any surfactant, or in a solution [aqueous or organic] in combination with at least one of the three classes of anionic surfactants, the linear alkyl benzyl sulfonates (LABS), alpha olefin sulfonates (AOS), and secondary alkane sulfonates, e.g., in an aqueous solution having a pH of at least 8.5 (e.g., between 8.5 and 13, between 8.5 and less than 11.5, or between 8.5 and 10.5) into any one of the first five steps described above, particularly the prep rinse, soak, main wash, rinse and clear coat applications can improve the driability of the washed structure. This is particularly true when the combination of anionic and cationic surfactant is added before or during the main wash. It has also been noted that the addition of the defined class of poly[oxyalkylene] ammonium cationic surfactant to the prep rinse and/or the soak, without the addition of the anionic surfactant species improves driability of the cleaned and washed surface.
The practice of certain aspects of the present invention has been found to provide uniquely beneficial effects in certain specific washing sequences, even where there are already general benefits provided in all washing, rinsing, or cleaning situations. The alkoxylated cationic ammonium cationic surfactant has been found to provide a particularly unique effect in the washing/rinsing/cleaning/waxing/drying cycles encountered in the washing of vehicle surfaces. When the alkoxylated ammonium cationic surfactant is present in an effective amount (e.g., greater than 5 parts per million (ppm)) in at least one of a series of liquid application steps in a washing/rinsing/cleaning/waxing/drying sequence, and the application is in any step before drying, the liquid is removed from the washed surface more rapidly (by sheeting, shedding, or physical movement of the liquid rather than evaporation) than with other compositions, and in some cases more completely before active drying (by towels or heated air or air drying). This feature is uniquely beneficial in the surface cleaning industry, and especially the vehicle cleaning industry. As vehicles are washed, cleaned, rinsed and then usually air dried or blown dried. The first method of drying allows for the formation of drying spots or water spots on the surface, if all of the liquid with any solids content has not been removed from the surface before air drying. The same problem occurs to a lesser extent with the blow drying (whether heated or not), and the time and energy involved in extended forced drying is reduced when there is less liquid remaining on the surface at the beginning of forced drying process.
In addition, there is a less quantifiable, but definitely observable benefit in the use of the poly[oxyalkylene] ammonium cationic surfactants in wash applications, particularly to car and vehicle bodies during wash operations. There is a visible improvement in the xe2x80x98shinexe2x80x99 or shininess of the surface when the poly[oxyalkylene] ammonium cationic surfactant is present in wash compositions than in similar wash compositions tried. This is believed to be a result of the fact that fewer adverse, shine reducing materials remain on the surface either from the original road film (remaining on the surface or redepositing on the surface from solution that is not removed) and/or from materials in the wash solution which deposit on the surface.
The exact functional mechanism by which the alkoxylated ammonium cationic surfactant affects the drying cycle in a washing/rinsing/cleaning/waxing/drying is not understood. This renders it all the more surprising that an unknown phenomenon is occurring in the application of the alkoxylated ammonium cationic surfactant that provides this unexpected benefit.
Examples of washing compositions include:
I. A washing composition used as an aqueous solution at a pH between 2.0 and 13 comprising:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, and secondary alkane sulfonates, and
b) at least one poly[oxyalkylene] ammonium cationic surfactant, The use of this particular washing solution (as applied solutions 1a) then 1b) at a pH between 1.0 and 6.0, with the addition of acidulating (or acidifying) agents, has been found to be particularly and surprisingly effective in areas where the water source has high water hardness and high TDS.
II. A washing solution used at a pH between 8.5 and 13 comprising:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, alkyl sulfates, and secondary alkane sulfonates,
b) at least one poly[oxyalkylene] ammonium cationic surfactant, and
c) an alkaline agent.
III. Another useful washing composition that is used at a pH between 8.5 and 10.3 comprises:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, alkyl sulfates, and secondary alkane sulfonates, and
b) at least one poly[oxyalkylene] ammonium cationic surfactant,
c) an alkaline agent, and
d) a chelating agent.
Each class of washing solution operates particularly well within and around the respectively described pH levels at the substrate surface. These pH levels would tend to be slightly higher in either a diluted solution or concentrate (e.g., 0.1 to 0.7 or more pH units higher) as compared to the pH on the surface of a vehicle to which the solutions were applied after application of an acid prewash. It has been surprisingly found that where the pH of the diluted solution (introduced as either a single step composition application or various solutions applied in multiple steps) while on the surface being cleaned (i.e., over at least a portion of its dwell time on the surface) is between about 8.5 to 11.0 or between about 9.0 and 10.5 (e.g., a surface contact pH between 8.5 and less than 11.5 or between 8.5 or 9.0 and 10.3 or 11.0), the general cleaning activity of the wash solution is significantly enhanced and even visually observable improvements in cleaning can be provided. The concentration of the alkoxylated ammonium cationic surfactant can be varied over a wide range, and the variations have been shown to have significant effects dependent upon which solutions are being used. Although the alkoxylated ammonium cationic surfactant may be used in concentrations of from about 3 to 1000 parts per million in the diluted or use solutions, they are more desirably provided in amounts of from 5 to 500, or 10 to 400 ppm in solutions applied with a chelating agent or after application of the chelating agent. The higher levels of the alkoxylated ammonium cationic surfactant may be particularly beneficial in waxing or polish liquids, the alkoxylated cationic ammonium cationic surfactant acting to provide a significantly and observably better shine when applied in these compositions during the wash cycle. The amounts of the alkoxylated ammonium cationic surfactant applied in these polish or wax compositions may be better provided in the higher end of the concentrations, from 10-1000, from 50-1000, or from 50 -500 ppm. in the particular composition.
The lower levels of the alkoxylated ammonium cationic surfactant may be desirable in the earlier applied compositions, especially any preparatory or prescrub liquid compositions, but this may be in part dependent upon the specific type of road soil encountered. For some types of road soil, it has been found that larger amounts of the alkoxylated ammonium cationic surfactant may reduce the ability of a specific component of the soil from being removed, while the lower concentration still actively assists in the removal of that specific component. In all concentrations of alkoxylated ammonium cationic surfactant, however, the compositions of the invention still actively clean surfaces in an advantageous manner.
The compositions of the present invention and wash sequences using compositions of the present invention wherein at least one liquid applied during the wash cycle comprises at least 5 ppm of at least one alkoxylated ammonium cationic surfactant have also been observed in some specific events to provide a unique benefit in cleaning vehicle surfaces at lower temperatures. It is known in the industry that when vehicles are washed at lower temperatures (e.g., below 60xc2x0 F., below 50xc2x0 F., below 40xc2x0 F. or below 30xc2x0 F., that is below 18xc2x0 C., below 13xc2x0 C., below 4xc2x0 C. 1xc2x0 C.), the road soil tends to be harder to remove. It is not fully understood whether this is caused by reduced activity of wash components because of the reduced temperature, or other phenomenon, but the poorer cleaning results are apparent. It has been found in the practice of the present invention that when one or more of the wash solutions of the present invention are applied to vehicles wherein the body temperature of the vehicle and/or the air temperature of application are at lower temperatures (as defined above), the washing cycle provides for a better cleaning than other wash systems. As the use of the alkoxylated cationic ammonium cationic surfactants are novel in vehicle wash systems and this benefit is unexpected from any teachings of the prior art, the process comprising the following steps is also novel and unobvious. The process comprises:
A process for cleaning the exterior surfaces of a vehicle comprising applying a first liquid to the exterior surfaces of a vehicle and then applying a second liquid to the surface of the vehicle, at least one of said liquids comprising at least 5 ppm of at least one poly[oxyalkylene] ammonium cationic surfactant, wherein the temperature of the surface of the vehicle is less than 60xc2x0 F. (below 18xc2x0 C.) and/or the air temperature and/or solution temperature at which the at least one of said liquids comprising at least one poly[oxyalkylene] ammonium cationic surfactant is below 60xc2x0 F. (below 18xc2x0 C.). The process may also be characterized as a process for cleaning the exterior surfaces of a vehicle comprising applying a first liquid to the exterior surfaces of a vehicle and then applying a second liquid to the surface of the vehicle, at least one of said liquids comprising at least 5 ppm of at least one poly[oxyalkylene] ammonium cationic surfactant, for where at least one liquid comprises an aqueous solution at a pH between 8.5 and 13 comprising:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, and secondary alkane sulfonates,
b) at least one poly[oxyalkylene] ammonium cationic surfactant, and
c) an alkaline agent;
wherein the temperature of the surface of the vehicle and/or the air temperature and/or solution temperature is at or below said lower temperature (e.g., below 60xc2x0 F., e.g., below about 18xc2x0 C.).
At least one of the liquids applied with or after or before the application of the at least one poly[oxyalkylene] ammonium cationic surfactant may comprise a chelant (as defined and described hereinabove) or the first application of the at least one poly[oxyalkylene] ammonium cationic surfactant may include a chelant, it being within the scope of the invention to apply a chelant before application of the at least one poly[oxyalkylene] ammonium cationic surfactant. It is also desirable in one practice of the present invention, particularly where certain types of road soil may be present on the vehicle to include a nonionic surfactant, as described above with at least one of the liquids applied. The nonionic surfactant may in fact be beneficially combined into a liquid comprising both the anionic and the at least one poly[oxyalkylene] ammonium cationic surfactant. The three different classes of surfactant and the chelant may therefore be applied in a single liquid composition. A particularly useful class of non-ionic surfactants that have never been used in vehicle wash compositions before include the class defined as alkoxylated amines or, most particularly, alcohol alkoxylated/aminated/alkoxylated surfactants. These compounds include such chemicals as aminotrimethylene phosphonic acid; aminodimethylenemonoethylene phosphonic acid; aminomonomethylenediethylene phosphonic acid; aminotriethylene phosphonic acid; aminomethylene-ethylene-propylene phosphonic acid; and the like. These non-ionic surfactants may be at least in part represented by the general formulae: 
wherein R20xe2x80x94 is an alkyl, alkenyl or other aliphatic group, or an alkyl-aryl group of from 8 to 20, preferably 12 to 14 carbon atoms, EO is oxyethylene (as previously defined), PO is oxypropylene as previously defined, s is 1 to 20, preferably 2-5, t is 1-10, preferably 2-5, and u is 1-10 preferably 2-5. Other variations on the scope of these compounds may be reprsented by the alternative formula:
R20xe2x80x94(PO)vxe2x80x94N[(EO)wH][(EO)zH]
wherein R20 is as defined above, v is 1 to 20 (e.g., 1, 2, 3, or 4 [preferably 2]), and w and z are independently 1-10 and preferably 2-5.
These compounds are represented commercially by a line of products sold by Huntsman Chemicals as nonionic surfactants. A preferred chemical of this class includes Surfonic(trademark) PEA 25 Amine Alkoxylate. It has been found, not only within the compositions of the present invention, but alone, in aqueous solutions, organic solutions, and mixtures with other surfactants (anionic, cationic, non-ionic, amphoteric, Zwitterionic), basic solutions, or acidic solutions that these alcohol alkoxylated/aminated/alkoxylated surfactants of this class are particularly effective in the removal of hydrophobic materials, particularly highly hydrophobc materials including grease, oils, greasy materials, and/or oily materials which may appear in soils, even though these individual materials may have very different physical or chemical natures. Examples of the hydrophobic materials or components of road soil that have been specifically identified as being cleanable by this class of materials includes, for example only, triglycerides, cable grease (e.g., Del Ray Cable grease based on fatty ester), fatty esters, divalent fatty acid salts, Mo (probably MoS2 or MoSi2), and Sb; and other highly hydrophobic greases with high temperature melting characteristics.
Another variation within the practice of the present invention is the use of an acidic presoak liquid or prescrub liquid, before, after or at the same time as the application of the liquid compositions comprising the at least one poly[oxyalkylene] ammonium cationic surfactant, such as the liquid comprising the aqueous solution at a pH between 8.0 and 13 or between 8.5 and less than 12.0 or less than 11.5 (with a chelating agent present) or between 8.5 and 10.5 (with a chelating agent present) comprising:
a) at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, alkyl sulfates, and secondary alkane sulfonates,
b) at least one poly[oxyalkylene] ammonium cationic surfactant, and
c) an alkaline agent.
The acidic presoak or prescub liquid would comprise a solution at a pH of between 1.0 and 5.5, or between 1.5 and 5, or between 2.0 and 5.0 comprising an acid (such as phosphoric acid, oxalic acid, tartaric acid, acetic acid, formic acid, trichloroacetic acid, glycolic acid, chloracetic acid, bromacetic acid, cyanoacetic acid, thioacetic acid, propanoic acid, barbituric acid, succinic acid, butanoic acid, uric acid, itaconic acid, 2-oxoglutaric acid, pentanoic acid, picric acid, picolinic acid, citric acid, isocitric acid, carboxyglutamic acid, 2-oxo-3-methylpentanoic acid, adipamic acid, adipic acid, hexanoic acid, 2-bromobenzoic acid, benzoic acid, 3-chlorobenzoic acid, 2-iodobenzoic acid, dinicotinic acid, dipicolinic acid, lutidinic acid, 2 or 3-nitrobenzoic acid, quinolinic acid, gallic acid and the like) and at least one surfactant. The surfactant may be any non-ionic, anionic, amphoteric or Zwitterionic surfactant known in the detergent art, as this liquid is merely a preparatory, presoak, or prescrub liquid application. The pH of the acidic solution on the surface should be within the described pH range. When the next liquid is applied, that next liquid will raise the pH level of the liquid on the surface of the vehicle. There will be a dwell time of the various liquids on the surface, with a alkaline liquid being applied to the vehicle surface during at least a part of the dwell time of a previously applied acidic liquid. By partial dwell time it is meant that some of the previously applied liquid may have run off the surface, dripped off the surface or evaporated, but that there is still visible liquid on the surface of the vehicle from that previous liquid application, either as a film, droplets, beads, patches, or the like. The application of an alkaline wash solution, including the alkaline wash solutions of the invention which comprise the at least one poly[oxyalkylene] ammonium cationic surfactant, will cause the pH of the liquid dwelling on the surface of the vehicle to rise to above pH 7, as the pH of the alkaline liquid will decrease, although remaining at a level above about 8.5 as described above. The pH may be measured by any convenient method, including, but not limited to the presence of a pH indicator strip on the surface of the vehicle, the use of pH measuring electrodes attached to the surface (for testing purposes), the placement of pH measuring devices onto the surface, and/or the removal of liquid samples from the surface and the measuring of the pH by conventional pH measuring devices and systems. The benefits of this aspect of the invention result with this acid first liquid application followed by a basic second liquid application, and, in fact, may be used in combination with any sequence of acid then alkaline material or alkaline material then acid, as well as with any other features, compositions or practices described herein. Where terms such as first liquid or second liquid are used, the numeric references imply order only when so specifically identified. In the practice of the application of the terminology xe2x80x9cacid first liquid application followed by a basic second liquid application,xe2x80x9d the term xe2x80x9cfollowsxe2x80x9d clearly identifies a required order or sequencing of the steps. Without such limitation, the reference to a number for the steps herein includes both the specific stated ordering and any reordering (e.g., applying a second liquid first) within the scope of the language.
The pH change in the later applied alkaline solution tends to be particularly important where a first later applied solution or a second later applied solution (later with respect to the first in sequence applied acidic liquid) contains a chelating agent, particularly the chelating agents according to the practice of the present invention such as the aminopolycarboxylic chelating agents such as HEDTA and EDTA and DTPA. The use of the lower pH (acidic) earlier applied liquid in combination with the later applied basic chelating agent containing liquids has been found to provide uniquely effective cleaning for a wide variety of components in road soil, and a high degree of cleaning and brightness to the cleaned surface.
One type of preferred cleaning or wash liquid in the practice of the present invention would comprise an anionic surfactant (particularly those from the class comprising at least one anionic surfactant selected from the group consisting of linear alkyl benzyl sulfonates, alpha olefin sulfonates, and secondary alkane sulfonates), at least one cationic surfactant comprising at least one poly[oxyalkylene] ammonium cationic surfactant, at least one non-ionic surfactant (as defined and described above), at least one alkaline agent (as described above), an aliphatic or aromatic or mixed aliphatic-aromatic hydrocarbon, oil or spirit (e.g., mineral oil, mineral spirit, terpene, limonene oxide, limene, terpentine, and the like), hydrotrope (e.g., dispersing or emulsifying agents, coupling agents, amphoteric agents, compounds having a hydrophilic-htdrophobic balance within the range of 2-16, oxygentade solvents such as the Dowanol(trademark) series and the like), and the various other types of general ingredients described herein and in the art in general. Such general ingredients might include, for example, thickening agents, antioxidants, dyes, organic solvents, silicates, and the like.